A device for adjusting sensor signals is disclosed in European Patent Application No. 0 264 388. This application describes a device for adjusting the output signal of a pressure sensor. To this end, a bridge circuit which comprises two pressure-dependent resistors is connected to an evaluation circuit. The pressure-dependent resistors are used as sensors. Given the same pressure values, resistance values vary from sensor to sensor. To produce a fixed relationship between the quantity to be measured and the output signal from the evaluation circuit, an adjustable resistor is provided. The adjustable resistor is connected in series to the sensor. A compensation circuit, which is quite costly, is required to compensate for the temperature drift of the adjustable resistor. For such devices, the adjustable resistors or the compensation circuit for the temperature drift are usually integrated in the evaluation circuit. As a general rule, if such a sensor is replaced, the evaluation circuit must also be replaced. In addition, the evaluation circuit must be tuned to the specific sensor.
Furthermore, European Patent Application No. 0 114 235 discloses a method for measuring the oxygen content in the exhaust gas of an internal combustion engine. To this end, a defined voltage is applied to a measuring resistor. The current flowing through the resistor is a measure of the oxygen concentration in the exhaust gas. The supply voltage for the measuring resistor is adjusted dependent upon the current measured at the time. It is not foreseen to compensate for variances.